Mallet finger

Mallet finger refers to a deformity of the distal interphalangeal (DIP) joint, typically caused by a rupture or avulsion of the extensor tendon at its insertion into the distal phalanx. This results in an inability to actively extend the DIP joint, leaving the fingertip in a flexed position. It commonly occurs due to a direct impact to the extended fingertip.

Use this code for documented cases of mallet finger, which may be described as a "baseball finger" or "drop finger." This diagnosis is supported by clinical findings of a flexed DIP joint that cannot be actively straightened, often following trauma. Documentation should clearly indicate the specific finger affected if known, though this code is general.

• This code specifies the condition, not the cause (e.g., fracture vs. tendon rupture).
• Do not confuse with boutonnière deformity, which involves the PIP joint.
• Consider laterality if documented, though ICD-9-CM 736.1 does not allow for specific laterality.